Multispeed drive axle



Aug. 17, 1943. l.. R. BUCKENDALE MULTISPEED DRIVE AXLE Filed OGC. 3, 1941 Lazare/7c@ Ba Patented Aug. `17, 1943 met? Smits i e-gaiaj The present inventionrelates to power transmitting mechanisms and is'v more-particularly concerned with automotive and similar drive axles embodying multi-speed gear reducing mecha# nisms, yalthough it is not limited to such use;

YSingle 'reduction worm drive V axles have been in successful use forpmany years, due to'their quietness of operation, the comparatively greatly increased speed reduction which is possible over that obtained with a bevel gear set of comparable size, and their long life and ability to stand up under extremely severe service conditions. n

It is the major object of this invention to p rovide a drive axle having all of the advantages:

of the worm drive axles heretofore used, and

the further important advantage` of being selec tively shiftable to decrease the speed ratio of the axle and aordmore efiicient operation under load and road conditionsnot requiring the full speed reduction of the worm drive, 'and yet retaining the highly desirable characteristics of quiet operation, ruggednessA and durability.`

A further vimportant object is to provide a drive` axlehaving a worm gear mechanism and a planetaryoverdrive mechanism arranged in series and operable to transmit power selectively at either the speed ratio of the worm gearingv orv at a ratio less than that of the worm gear mechanism. l Y, 1 g y Another object is'tovprovde aV drive axle, have ing a main housing, with an auxiliary housing carrying a unitary worm gear and-planetary gear mechanisms and operable totransmit power from y the drive shafts to the axle shafts.

iA further object is to provide novel means for` journalling the diierential casingY in the plane-- tary rotor. Y i

` Further objects are to provide a multi-speed drive axle having a novel rotor and worm gear assembly, av novel speed selecting and shifting mechanismV and to provide other subordinate improvements and refinements.y

Further objects will become 'appre'nt 'as theV specification proceeds-in conjunction with ther annexed drawing, and from Ythe appended claims,

In the drawing the single figure is a longitudinal vertical-sectionA through a drive axle emr bodying the invention, the housingw below fthe',

center line being shownin elevation to simplify thedisclosure. The axle embodies a main housing IiLhaving a pair of axle shafts i I.' and I2 mounted for rotation thereinin well-known manner and drivingly connected to vehiclel wheels or other 'drive means (not shown)- Housing member HJV isr preferably .plug I3.

mechanisms are supported as 'a novel .unitary assembly'upon a carrier structure i4 having a' f flange i5 detachably isecured'to housing YIB vbyl made of a single casting, aording maximum' strength, andis provided withalubricantdrain Both they Worm and planetary 'gear means of screws 16. Carrier i4 has a piloting surface HV which cooperates-with an opening I8 in the housing toi-accurately align-the parts, the mating plane of the housing sections 'being disposedl substantially parallel to the driveY axles.-`

Mounted for rotationin spaced vanti-friction bearings (not shown) in carrier' i4 is aworm ISL' to which power `may be appliedvin any suitable manner, as or-` instance by means of the propellerY shaft of an automotive vehicle. 'Arpair of 'reser-yy YVoirs 2i and l22 1are preferably'integrallylformed-l i 'inwcarrier M to collectthe oil vth'rownfirom the worm during operation and feed it to the Worm' Vshaft bearings showm': Y a

-` By mounting the entire gear mechanism in 'by l.way of suitable'rducts (not Avnovel unitary manner inthe auxiliary housing' as will now be described, an extremelysimplev yet rugged construction is' provided and one which maybe readily disassembled forservicing and repair.

Compactly 'disposed in carrier l isarotorf structure made upof a pair of end sections 2li and 25, and an intermediate section 26. Sections 24 and 2G are `detachably-secu'red together fby stud andnut assemblies 21'. Detachably clamped between sections 25 and 26 is a worm gear 28,VA

which lconstantly meshes with, worm l9. Thel` parts are secured together by stud andnut ase,l Y

semblies 29, andin order to insure accurate centering o`f the: gear, se'ctions25 and 26 are providedY with accurately formed cylindrical pilotingsurfaces .3| vand 32, respectively, which snugly t mating surfaces33 and @t on gear 28.. l

The rotor structure issupported on the carrier by means -of downwardly projecting cylindrical bearing mounts 35 and 36, which co-ntain antifriction bearings 31 and 3 8 cooperating withl hub portions 39 andvfl, respectively, formed on rotor sections 24 and 25.` The bearings are adapted to be adjusted by ring members d2 and` 43, `threaded into the bearing supports, and having axially directed ilanges coacting with the outer bearing races.

bers are also provided with axially directed teeth,

adaptedto. cooperate with a locking 'mechanism` of any suitable character `(not shown-lf, whereby Member?,r is also provided with a plua l rality of internal teeth 4d for a purpose that will .presently appear. The `bearing adjustment mem- The axle shafts are splined to differential side` gears 45 and 46, whichmesh with a plurality of differential miter gears 41 carried by a spider 48 in Well known manner. Y

The rotor is, accordingly, driven by the con' stantly meshed worm and worm gear at a speed reduction, the ratio depending upon the pitch of the gears, it being understood `that aratio will be chosen to suit the requirements of the particular installation involved. Power is adapted to be selectively transmitted from the'rotor. assembly to the axle shafts at either a oneto-one ratio or at a speed increasing ratio, the latter giving an overall ratio less than'that of the worm gearing, per se, so that under light load conditions more economical operation may be secured.

Tightly tting in openings in rotor section24 and Yalso in Ya ring member 49, are a plurality of planet shafts '5L to'section 24 at circumferentially spaced points intermediate the planet shafts by matching bossesv bolted in tight engagement in well -known mannerY (not shown).

Mounted upon each shaft Y is a planet gear 52 whichconstantly meshes with sun gear -teeth 53 formed on a sleeve or quill member 54. The quill'is mounted for both axial androtative movement in the'housing and is provided with aV second series of external teeth 55, which are adapted to be meshed with teeth 44 of bearing adjusting member 42 to lock the quill againstV rotation. Sun gearteeth 53 are also adapted to f l be selectively meshed with a set of teeth 56 formed'inside hub 4| of the rotor for establishing a one-to-one ratio between the parts, as Will presently appear. Y

The qunris adapted to be shifted. into its var-y .d

ions longitudinal positions by means ofv a yoke 51 having a pair of pins 58 riding in a groove 59 in the quill. Yoke 51 is mounted on a shaft GI journalled in an auxiliary casing 62, detach#A ably secured over an opening B3 in housing I 0.. v ShaftV 6l is adapted to be rocked by any suitable. means, las for instance by means of a lever se.-

66, floats upon Ythe pitch lines of planet gears` 52, and since the latter are three or more in` number a stable support is afforded. The'righ't hand end of the casing, by reason of spider 48 and miter gears 4l (which arealso preferably. three in number) oats upon thepitch lines-of the side gears, which are journalled for accurate rotation in ring 64 and the hub 65 of rotorsection 25. Thecasing accordingly freely floats in therrotor and is supported at widely spaced points. j Endwise movement oi the casing, and also side gears 45 and `4t is-limited by means of webs Ring 49 is rigidly secured.

adjacent 2,326,755 v 69 and 1| on the casing, which have thrust washers cooperating with ring 64, the hub-of rotor section and the backs of the side gears,

Vit being understood. that the openings in the webs are suiizlciently large to avoid contact with vthe side'gear hubs, so as to avoid interferenceV tachably secured together by screws 12,`it being understood that the arms 0f spider 48 are clamped in place between the halves of the casing, in

well known manner.

'Il are also provided with a plurality of openings V'I3 andY V14, respectively, for allowing lubricant introduced into the casing by a scoop mechanism of the character shown in my co-pending application for Drive axle, Serial` No. 413,537, filed of even date herewith. s f l -.V Operation With the partsdisposed in. the .position shown in the drawing, with planets 52 Aengaged with sun teeth 53, and with teeth of` the quill en gaged with stationary teeth 44, rotation of worm I9, by means of any. suitable prime mover, drives worm wheel 28 at reduced speed and lthe planetary rotor synchronously therewith. Rotation of the rotor, 'as just described, through rotor section 2,4,.causes planet shafts 5| to travel in an orbit, carrying planets 52 Vwith them. Travel of the planets in an orbit under the conditions just described` causes them to planetate .through their Vengagement with'stationary sun gear teeth 53,

and this results in their .drivingthe orbit orl ring gear 65 `at an increased rateof speedvor atan overdrive ratio. The power; isin turn transmittedv from the ringV gear to Vcasingy'l, and the latter, through spider 48 and gears 4l, divides the power between the tWova'xle shafts.

rIlhe overall ratio of the gearing'is accordinglylk Ahigher than that of the worm gearing alone,

withV the resultV that allthe desirable operating characteristics ofthe worm` drive are retained and in addition a higher speed ratio may be selectively Yobtained for more eflicient operation v underload and road conditions which do not require thegreater gear reduction of the worm gear..A v .l

Assuming no'wtliatuthe quill is shiftedto the left, suiiiciently to disengage teethl 55 from stationary teeth 44, but insuiciently to engagesun gear teeth` 53 with teeth 5670i the rotor, the parts are disposed in neutraL Under these conditions rotation of the rotor does not result in transmission of power because .travel of shaft 5l and planets I52 injanorbit merelyA resultsv in their teeth idly meshing with sun gear teeth 53 and ring gear 6B. .f

Y Assuming now that shaft 6I` is rocked so as to shift the `quillintor its extreme left hand position, with sun gear .teeth 53 meshing with internal teeth 56, but yet Vretaining partial engagement with the planets, the-quill is locked to the rotor so as to rotate synchronously therewith and the quill locks the planets against rotationv about their axes. Rotation of the rotor under these conditions, accordingly, causes the quill and the locked planets tov rotate casing 61 synchronously with the rotor, at a one-to-one or direct drive ratio. Under these conditions, the full gear reduction of the worm gear mechanism is utilized.

Journal portions 69 and I thee'device.

extreme right-hand position andthe carrier is.

It is be understood that the shift into the various speed ratios maybe effected in' any d'esired manner. AIVFor instance, infan automotive vehicle, the power may bemomentarilyinterrupted, as, for instance, by disengaging the vehicle clutch, or, if. desired, any well known type of shift facilitating featuremay be incorporated in the mechanism without impairing its action being split transversely ofsaid axleshafts into; a cylindrical central section and a pair of end sections; a worm'g'ear detachably clampedb'e- Y I tweenk said central sectioniand oneof vsaidend and enabling the shifts to be carried out without]- disengaging the vehicle clutch. easy shift feature of the copending application if desired, the i of Nelson R. Brownyer, Serial No.'387,977, filed.

April 10, 1941, for Power transmissionv mechanism, may be employed without departing from' the spirit of the invention.

Disassembly of the unit is readily eiected by removing screws it, so as to free the carrier, and removing casing 52 withitsattached lshaft and two different speed ratios' housedjwithinsaid f yoke assembly, the quill preferably being in its extreme left hand position duringVY this operation. Axle shafts H and l2 are removed, either before g or after the operations justdescribed so as to Y.

leave the rotor unattachedv to any other part of The quill is then shifted into its lifted, so ask to cause the teeth of rings t'and Btc pass through recesses @2a and flea. Upon contact of theend of the quill with the inner wall of the housing adjacent teeth fmjthe carrier assembly is rocked counterclockwise so as to olea.

the right hand end and the assembly then lifted clear of the housing. The unitary carrienworm gear and rotor may then be completely disassem- Abled. on the bench by removing the lower halves of bearing supports 35 and 36 (not shown). The mating planes of the sections of casing El and the rotor are closely/'adjacent each other, so that upon separation their entire interiors are acces-r sible.

From the foregoing detailed disclosure of the sections, said casing also being split transversely of said axle `shaftsinto two sections, a fdiierem Y tial mechanism insaid casing and having'a spider y secured between said casing sections', said dif- Vferential mechanism. being Yaccessible for -disas' sembly upon separation `of said casing sections ;A i and planetary mechanism for` selectivel'ytransmitting power viromsaid rotorto said casing at central section and accessible upon separation of the other f said end sections from said central section. 1

2. The drive axle denned inclann'l,whereinA said one rotor en d. section YisA` joined to saidgear alonga vplane adjacent the transversev split in said casing. Y

3. In a power transnittinglmechanisni,'a hcusing; a rotor journalled for" rotation about a iixed raxis in said housing and carrying a plurality of circumferentiallyjspaced shafts; a planet gear o-n each of. lsaid shaftsa vpair ofdiierential sideV gears kmounted for independent rotationin saidA .l

rotor; 'a Ycasing structure disposedin said rotor( and rigidlycarryingvat one end an orbitgearV meshing Withsaid `planet gearsp'andY a spider carrying miterg'ears'meshing with said side gears and secured adjacent the other end of ,said casing, said :orbit gear being `.operable to Iride on the pitch. circles of said planet gears and constituting the solefrotatable support for said'one end ofl said casing.

invention, it is apparent that there is provided a l Worm drive and embodying a twospeed planetary gear mechanism affording a Wide range of speed o ratios, making possible the iull'utilizationof the speed reduction of the worm drive under heavy load conditions, and which may be readily shifted to decrease thetorque multiplying action of theY worm gearing and afford more efficient operation underlighterv loading conditions, the advanta geous operating characteristics of the worm gearing being retained at all times.

The invention maybe embodied in other spe-V cific forms without departing-from the spirit or essential characteristics thereof. The present.

embodiment is therefore to be considered in all respectsas illustrative and'not restrictive, the scope ofthe invention beingindicated by the appended claims rather than by the foregoing description, and all changesY which come within the meaning andrange of' equivalency of the kclaimsare therefore intended rto be embraced therein. What is claimed and .desired to be secured by United States Letters Patent is:

1. In a drive axle, a housing Y compact, eicient power transmitting mechanism of simplevand rugged construction providing a -aligned'drive axles rotatable therein carrying side gearsat theirneighboring ends; a rotor mounted having a pair of Y A. a. The powertransmitting mechanism dened l in claim 3, wherein saidjmiter gears arev adapted A to vride on the V pitch circles of said sidel gears and constitute the sole rotatable support forsaid v other end of'said casing. A5. The power transmitting mechanism deiined in claim;3, togethe r with means for limiting'axialY A movement of saidfcasing in either direction. Y

` v6. In a Vdrive axle, a housing havingja pair of for rotationin said housing aboutthe axis Y:of

said axles and adapted to have power applied.'V

thereto; a plurality of circumferentially spaced shafts lprojecting from said rotorjand each rotat` ably supporting a'planet'gear; a casing in said rotor having an internal gear at one lend meshing Withvsaid planet gears Yand having a spider .adjacentV the otherl end carrying miter gears meshing with said sidegears, thelatter and said planet gears constituting the sole rotatable support for said casing; and a pair oi axiallyspaced -shoulders on said casing engagingv opposing faces onl said rotor, forA limiting relative axial "movement'of said casing-and rotor; and also'engaging axiallyY directed faces on said side gears 'for limiting movement thereof awayfiom each other.'r

- LAWRENCE n isuciznNoann 

